Clinical evaluation of adjunctive Nd:YAG or diode laser application for non-surgical periodontal therapy: a systematic review with meta-analysis

Objectives: This systematic review and meta-analysis aimed to evaluate the role of diode and Nd:YAG lasers as adjuncts to scaling and root planing (SRP) in the non-surgical treatment of moderate-to-severe periodontitis. Methods: The protocol was registered in PROSPERO (CRD420250603025) and conducted following PRISMA guidelines. A comprehensive search in Scopus, PubMed, and Cochrane CENTRAL (up to October 2024) identified randomized controlled trials (RCTs), prospective, and retrospective controlled clinical studies comparing SRP alone versus SRP plus adjunctive laser therapy. The primary outcome was probing pocket depth (PPD); secondary outcomes were bleeding on probing (BoP) and the clinical attachment level (CAL). Risk of bias was assessed using Cochrane RoB 2.0 tool for RCTs and Newcastle–Ottawa Scale for non-RCTs. Meta-analysis was undertaken when at least three studies presenting the same outcome at the same follow-up were found. Results: Nine studies with follow-ups from 3 to 120 months were included, representing a total of 423 participants. Both groups showed PPD reduction at all time points, with pooled analyses revealing no statistically significant differences (mean difference −0.12 to −0.35 mm; p > 0.05), although point estimates often favored laser-treated sites, particularly when baseline PPD ≥ 6 mm. Subgroup analysis showed significantly greater PPD reduction in laser-treated sites compared to SRP alone at 12 months in deep pockets (p = 0.001). These findings should be interpreted with caution, given their exploratory nature, limited sample size, and high heterogeneity. Similar patterns were observed for CAL and BoP, with substantial heterogeneity (I2 > 70% at several time points). No adverse events were reported. Conclusions: Within the limitations of the available evidence, adjunctive diode and Nd:YAG laser therapy does not demonstrate consistent statistically significant differences compared to SRP alone in non-surgical periodontal treatment. While a potential adjunctive effect may be observed under specific clinical conditions, particularly in deeper pockets, current evidence is insufficient to support its superiority.